I have a fix! It requires changing just ONE word in One line of the code. It works fine with my Moodle 2.0.1 site but I don't have any journal assignments in my Moodle 2.2 site to try it on. Maybe tomorrow. So, I took a chance and ran it on my Moodle 2.6dev site and it worked there too...after I ran the assignment converter. When it converts a journal it makes it into the old assignment versions, so the more recent Moodle's you need to run the assignment converter. In fact, in Moodle 2.6 it was hidden even from me as admin until I tried running the converter, and it was listed there as needing to be converted to the new assignment format.
Here is the fix..in journal2assignment.php, line 97, change the word "assessed" to "grade" and that's all that needs to be changed.
If you need me to, let me know and I will upload a copy of the file.
As usual, I would recommend backing up you site or trying it on a development site first.